Controlling apparatus for highway crossing signals



March 28, 1939. G. R, PFLASTERER 2 76 CONTROLLING APPARATUS FOR HIGHWAYCROSSING SIGNALS Original Filed June 30, 1936 -Re2fazlned NeutralPolarged Relay.

Fig.1.

' 22x13 17R Retained Neuiral 1 19'. 2. olari ed in?) y- [Zeamed Neutral(2 4 2) H polfzrz' ed Relays. 4 K-f-zz" 2T +7 f /5T 47 1 H 2 4+ 4 .9 Qii fi'g. 5.

B INVENTOR 18 220 17 George 13. asterer.

A I 1 H15 ATTORNEY Patented Mar. 28, 1939 UNITED STATES CONTROLLINGAPPARATUS FOR IHGHWAY CROSSING SIGNALS George R. Pilasterer, Greenville,Pa., assignor to The Union Switch & Signal Company, Swissvale, l?a., a.corporation of Pennsylvania Application June 30, 1936, Serial No. 88,103Renewed April 6, 1938 11 Claims.

My invention relates to controlling apparatus for highway crossingsignals, that is, to apparatus for the control of signals which areplaced at intersections of railways and highways for the purpose ofwarning users of the highway when a train is approaching.

I will describe three forms of apparatus embodying my invention, andwill then point out the novel features thereof in claims.

Fig. 1 of the accompanying drawing is a diagrammatic view illustratingone form of apparatus embodying my invention as applied to a stretch oftrack over which traffic normally moves in one direction only. Fig. 2 isa diagrammatic view illustrating a modification of the apparatus shownin Fig. 1 and also embodying my invention. Fig. 3 is a diagrammatic viewillustrating another form of apparatus embodying my invention as appliedto a stretch of track over which trafiic'moves in both directions.

Similar reference characters refer to similar parts in each of theseveral views.

Referring first to Fig. l, the reference characters 2 and 3 designatethe rails of a stretch of track over which trafic normally moves in thedirection indicated by the arrow. The stretch is divided by insulatedjoints 5 into two adjacent sections designated by the referencecharacters IT and ET, respectively. Each track section is provided witha track battery 4 connected across the rails at one end of the sectionand with a track relay, designated by the reference character R with aprefix the same as the reference character of the associated section,connected across the rails at the other end of the section. Locatedadjacent the right-hand end of section 2T is an intersection of therails of the stretch and a highway H. The highway H is protected by asignal S of any suitable type. As here shown, the signal S includes agreen lamp G for displaying a proceed indication, a yellow lamp Y-fordisplaying a caution indication, and a red lamp R for displaying a stopindication. The signal S is controlled by a polarized relay XR having aretained neutral characteristic. The relay XR is controlled by the trackrelays lTR and 2TB.

With both sections IT and ET unoccupied so that both relays lTR and 2TB,are energized, the relay XR is supplied with energy in the normaldirection so that the green lamp G- is energized. The circuit for relayXR may be traced from terminal B of a suitable source of energy overfront point of contact 6 of relay 1TB, front contact l of relay 2TB,relay XR, front contact 8 of relay 2TB, and front point of contact 9 ofrelay lTR to terminal C of the same source of energy. The circuit forthe green lamp G may be traced from terminal 13 through front point ofneutral contact Ill of relay XR, normal polar (Cl. 246-l3ll) 7 contactH-l2 of relay XR, and lamp G to terminal C.

I shall now assume that an eastbound train, that is, a train movingtoward the right, enters section IT so that relay lTR becomes released.

When relay lTR is released so that its back contacts become closed, therelay XR will be energized in the reverse direction. This circuit may betraced from. terminal B over back point of contact 9 of relay ITR, frontcontact 8 of relay 2TB, relay XR, front contact 1 of relay 2TB, and backpoint of contact 6 of relay ITR to terminal C. When relay XR isenergized in the re- Verse direction, the yellow lamp Y will becomeenergized to cause the signal S to display a caution signal. The circuitfor lamp Y may be traced from terminal B over front point of contact Inof relay XR, reverse polar contact ll--l3 of relay XR, and lamp Y toterminal C. When the train enters section 2T so that relay 2TB becomesreleased, energy will be disconnected from relay XB, to cause the redlamp R to become energized. The circuit for lamp B may be very readilytraced over the back point of contact VII! of relay XR. When the'trainvacates section 2T, relay XR will again become energized in the normaldirection so that the green lamp G will be lighted to cause the signalto display the proceed indication.

It will be understood that the length of sec tions iT and ET will be sochosen that users of the highway will have ample warning before a trainapproaching the highway reaches the intersection.

Referring now to Fig. 2, the apparatus illustrated herein operates in amanner similar to that just described for the apparatus shown in Fig. 1.The relay 2'IXR is directly connected across the rails of section 2T andthe track battery l is connected across the rails of section 2T bycontacts 6 and 9 of the relay ITR. It will be readily apparent that therelay ZTXR, will be supplied with energy in the normal or reversedirection according as the relay lTR is picked up or released,respectively, provided section 2T is unoccupied, and that the relay ZTXRwill be released whenever the section ZT becomes occupied. Thearrangement shown in Fig. 2, therefore, functions in a manner similar tothat described for the apparatus shown in Fig. 1, but eliminates thetrack relay 2TB, and the line conductors for the control of the signalcontrol relay.

Referring now to Fig. 3, the rails 2 and-3 are divided by insulatedjoints 5 into track sections ET, 2T, 3T, and GT. The sections lT and QTare each provided with the usual track battery 3 connected across therails at one end of the section and with track relays lTR and tTR,respectively, connected across the rails at the other end of thesection. The polarity of the energy supplied to sections 2T and, 3T iscontrolled by relays ITR. and 4TB, respectively, and each of thesesections is provided with a polarized track relay having a retainedneutral characteristic and designated by the reference characters2TXR'and 3TXR, respectively. Located approximately at the junctionbetween sections 2T and 3T is an intersection between the track railsand a highway H. The signal S is controlled jointly by the relays ZTXRand STXR and by an interlocking relay K having magnets M2 and M3. Withall sections unoccupied so that track relays ZTXR and STXR are energizedin the normal direction, both magnets M2 and M3 are energized. Thecircuit for magnet M2, for example, may be traced from terminal B overfront point of contact [4 of relay ZTXR, normal polar contact I5l6 ofrelay ZTXR, and magnet M2 to terminal 0. When both magnets M2 and M3 areenergized so that flagman contacts l1 and I8 are closed, the

' green lamp G of the signal is energized so that a proceed indicationis displayed.

I shall now assume that an eastbound train, that is, a train moving fromleft to right enters section IT so that relay ITR becomes released. Whenrelay [TR is released, relay 2TXR becomes energized in the reversedirection over the back points of contacts 6 and 9 of relay ITR. Whenrelay ZTXR is energized in the reverse direction, magnet M2 becomesreleased so that a circuit is completed for the yellow lamp Y to causethe signal to display the caution indication. The circuit for lamp Y maybe traced from terminal 13 over front point of contact M of relay 2TXR,reverse polar con-tact lE-IB of relay ZTXR, back point of contact 200imagnet M2, and lamp Y to terminal C. When the train enters section 2T sothat relay 2TXR becomes released, a circuit is completed for the redlamp R to cause the signal to display a stop indication. This circuitmay be traced from terminal B over back point of contact M of relayZTXR, back contact 2| of magnet M2, and lamp R to terminal C. When thetrain vacates section 2T and enters section 3T, relay ZTXR will becomeenergized in the normal direction to restore magnet M2 to its energizedcondition and relay STXR will become released to disconnect energy frommagnet M3. Because the relay K, however, is of the interlocking type,fiagman contact I! will not become open and back points of contacts 22and 23 of magnet M3 will not become closed. The green lamp G, therefore,will again become energized over the previously traced circuit for thislamp. When the train departs from section 4T, the relay 3TXR will againbecome energized in the normal direction so that magnet M3 will alsobecome energized and all apparatus will then be in its normal condition.

While I have described the operation of the apparatus shown in Fig. 3for an eastbound train only, it will be readily apparent how theapparatus operates for a train moving in the opposite direction.

As shown in the drawing, relays XR, ZTXR, and 3'IXR may be provided witha retained neutral characteristic to avoid a momentary display of thestop indication during pole changing periods. For example, in Fig. 1when relay ITR becomes released so that the direction of current flowthrough relay XR is reversed, the front point of contact I!) remainsclosed so that a momentary energization of the red lamp R is avoided. Ifthis feature is not considered to be worthwhile, relays of the ordinaryand usual construction may be substituted for the relays having theretained neutral characteristic.

From the foregoing description of the apparatus embodying my invention,it will be seen that I have provided the reliable means for displayingat a highway intersection a proceed, a caution, and a stop signal inaccordance with traffic conditions. In one form of apparatus shownherein, no timing devices are required and in other forms no timingdevices or line wires are required.

Although I have herein shown and described only three forms of apparatusembodying my invention, it is understood that various changes andmodifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track including an intersectionwith a highway, a first track section and a second track sectionincluded in said stretch and successively occupied by a trainapproaching said intersection, a track circuit including a track relayfor said first section, a pole changer including contacts of said trackrelay, a polarized relay governed by said pole changer and by trafficconditions in said second section, a highway crossing signal at theintersection capable of displaying three different indications, andmeans governed by said polarized relay for controlling said signal.

2. In combination, a stretch of railway track including an intersectionwith a highway, a first track section and a second track sectionincluded in said stretch and successively occupied by a trainapproaching said intersection, a track circuit including a track relayfor said first section, a circuit, means including front contacts ofsaid track relay for supplying said circuit with current of onepolarity, means including back contacts of said relay for supplying saidcircuit with current of the other polarity, a polarized relay energizedby said circuit provided said second section is unoccupied, a highwaycrossing signal at the intersection capable of displaying threedifferent indications, and means governed by said polarized relay forcontrolling said signal.

3. In combination, a stretch of railway track including an intersectionwith a highway, a first track section and a second track sectionincluded in said stretch and successively occupied by a trainapproaching said intersection, a track circuit including a source ofcurrent and a track relay for each section, a pole changer includingcontacts of the track relay for said first section, a circuit controlledby said pole changer and by contacts of the track relay for the secondsection,

V a polarized relay connected to said circuit, a highway crossing signalat the intersection capable of displaying three difierent indications,and means controlled by said polarized relay for governing said signal.

4. In combination, a stretch of railway track including an intersectionwith a highway, a first track section and a second track sectionincluded in said stretch and successively occupied by a trainapproaching said intersection, a track circuit including a track relayfor the first section, a source of current connected across the rails ofthe second section in one direction or in the other direction accordingas the track relay for the first section is energized or deenergized, apolarized track relay connected across the rails of the second section,a highway crossing signal at the intersection capable of displayingthree difierent indications, and means controlled by said polarizedrelay for governing said signal.

5. In combination, a stretch of railway track including an intersectionwith a highway as well as a first and a second track sectionsuccessively occupied by a train approaching said intersection from onedirection and a third and a fourth track section successively occupiedby a train approaching said intersection from the other direction, apair of polarized relays one controlled by tramc conditions in saidfirst and second sections and the other controlled by trafiic conditionsin said third and fourth sections, an interlocking relay governed bysaid pair of polarized relays, and a signal capable of displaying threedifierent indications governed jointly by said interlocking relay and bysaid pair of polarized relays.

6. In combination, a stretch of railway track including an intersectionwith a highway, a first track section and a second track sectionincluded in said stretch and successively occupied by a trainapproaching said intersection, a polarized relay, means controlled bytraflic conditions in said sections for energizing said relay in onedirection or the other according as said first section is occupied orunoccupied provided said second section is then unoccupied and fordeenergizing said relay when said second section is occupied, a threeindication highway crossing signal at said intersection, means governedby said relay for selectively controlling the three indications of saidsignal in accordance with the three conditions of the relay, anddirectional means controlled by traflic conditions in said stretch forremoving said signal from control by said relay when said sectionsbecome occupied by a. train receding from said intersection.

7. In combination, a stretch of railway track including an intersectionwith a highway, a first track section and a second track sectionincluded in said stretch and successively occupied by a trainapproaching said intersection, a polarized relay, means controlled bytraffic conditions in said sections for energizing said relay at normalpolarity when both sections are unoccupied or for energizing the relayat reverse polarity when said first section is occupied and said secondsection is unoccupied and for deenergizing the relay when said secondsection is occupied, a highway crossing signal at said intersectionoperative to display a warning indication and a stop indication, a firstcircuit controlled by said relay when energized at reverse polarity tocause said signal to display the warning indication, and a secondcircuit controlled by said relay when deenergizedto cause said signal todisplay the stop indication.

' 8. In combination, a stretch of railway track including anintersection with'a highway, a first track section and. a second tracksection included in said stretch and successively occupied by a trainapproaching said intersection, a polarized relay, means controlled bytraffic conditions in said sections for energizing said relay at normalpolarity when both sections are unoccupied or for energizing the relayat reverse polarity when said first section is occupied and said secondsection is unoccupied and for deenergizing the relay when said secondsection is occupied, highway trafilc controlling means to controlhighway trafiic at the intersection, a first circuit including a contactclosed only when said relay is energized at reverse polarity toestablish a first warning condition of said controlling means, and asecond circuit including a contact closed only when said relay isdeenergized to establish a second warning condition of said controllingmeans.

9. In combination, a stretch of railway track including an intersectionwith a highway, a first track section and a second track sectionincluded in said stretch and successively occupied by a trainapproaching said intersection, a. polarized relay, means controlled bytraffic conditions in said sections for energizing said relay at normalpolarity when both sections are unoccupied or for energizing the relayat reverse polarity when said first section is occupied and said secondsection is unoccupied and for deenergizing the relay when said secondsection is occupied, a highway crossing signal at said intersectionoperative to display a warning indication and a stop indication,

a first circuit means including a front neutral contact and a reversepolar contact of said relay to cause said signal to display the warningindication, and a second circuit means including a back contact of saidrelay to cause said signal to display the stop indication.

10. In combination, a stretch of railway track including an intersectionwith a highway, a first track section and a second track sectionincluded in said stretch and successively occupied by a trainapproaching said intersection, a track circuit including a track relayfor said first section, a track circuit including a current source and apolarized relay for said second section, means including front contactsof the relay for the first section to connect said source to the railsof the second section for energizing said polarized relay at normalpolarity, means including back contacts of the relay for the firstsection to connect said source to the rails of the second section forenergizing said polarized relay at reverse polarity, a highway crossingsignal at the intersection,

means including a reverse polar contact of the polarized relay foroperating the signal to display a first warning indication, and meansincluding a back contact of the polarized relay for operating the signalto display a second and different warning indication.

11. In combination, a stretch of railway track including'an intersectionwith a highway, at first track section and a second track section formedto one side of the intersection and successively occupied by a trainapproaching the intersection, a polarized relay, means controlled bytrafi'lc conditions in said sections for energizing said relay at normalpolarity or at reverse polarity according as said first section isoccupied or unoccupied provided said second section is unoccupied andfor deenergizing said relay when said second section is occupied, ahighway crossing signal operative to display a warning indication and astop indication, means including a reverse polar contact of the relay todisplay the warning indication of said signal, means including a backcontact of the relay to display the stop indication of said signal, anddirectional means controlled by trafiic conditions of said stretch torender said relay ineffective to display either the warning or the stopindication of said signal when a train recedes from the intersectionthrough said sections.

GEORGE R. PF'LAS'I'ERER.

